Process for treating synthetic oils



Patented Nov. 7, 1933 UNITED STATES PROCESS FOR TREATING SYNTHETIC OILSEdward M. Jollyand Charles C. Swoope, Baton Rouge,La., assignors toStandard Oil Develop ment Company, a corporation of Delaware No Drawing.Application December 5, 1930 Serial No.- 500,424

"5 Claims] (o1. 196-23) The present invention relates to an improvedmethod for treating lubricating oils andmore specifically to the removalof halogens from oils pr pared by condensation means. Our-invention willbe fully understood from the following description and the example whichillustrates one method of application of our process.

In the production of high grade lubricants, and in particular thelubricants prepared by condensation of organic halides or of organicmaterials in the presence of metallic halides, it is well known that thecomplete elimination of chlorine and other halogens from the finishedproduct is necessary, particularly with motor oils or oils which areadapted for machinery operation at high temperatures. For example, aresidue of as little as 0.1% chlorine is known to form combinations withiron and aluminum producing active cracking or polymerizing catalysts inthe cylinders and bearings of the engine. The action of halogen istherefore undesirable both because of its corrosive effects on theengine parts and because of its catalytic effect in promoting theformation of carbon and sludge from the oil. We have now found a methodwhereby chlorine and similar substances may be removed from thelubricating oils so completelythat not even traces of residual chlorinemay be found in the final oil. Our improved process consists essentiallyin treating the synthetic oil with reactive metal which is in a liquidcondition under the conditions of operation In the operation of ourprocess the condensed oil which has been found to contain traces ofchlorine or other halides is subjected to the action of a reactive metalsuch as an alkali metal or mercury at a temperature of about 300 F. to450 E, which is the preferred operating range. It will be understoodthat lower temperatures may be used which are ordinarily above themelting point of the particular metal say 210 F. for sodium for example,but usually the temperature range given above is preferred in order toobtain the most complete reaction within a reasonably short time, sayless than five or ten hours. The temperature may also beabove 450 F.even up to 600 F. or slightly higher, but it is preferably below suchtemperatureas causes appreciable thermal decomposition of the oil.

As an example of the operation of. the process the following is given:.

A hard parafiin wax having a melting point of 122 to 125 F. ischlorinatedv by the direction- The chlorine is blown through the oil forabout 24 hours and after this time it is found that the product containsabout 12% chlorine, although thereis some unchlorinated hydrocarbon. To

90 parts of this chloro-paraffin 10 parts of naphkerosene and theunreacted paraffin as distillates.

The heavy oil remaining has the following inspection:

Gravity 23.4: A. P. I. Vis. at 100 F 8500 sec. Saybolt Vis. at 210 F 312sec. Saybolt Pour 65 F.

Flash 535 F.

Conradson carbon 4.6% I

Residual chlorine .2%

This synthetic oil and similar oils prepare'diby condensation of organicchlorides contains small amounts of residual chlorine whichis normallybelow 1% and may be as low as .2 to 0.05 of 1% and is objectionable. Themajority of this chlorine may be removed by treatment with alumina,

bauxite, and the like, but ordinary treatment with these agents does notremove all the chlo- ,rine and we have found that a final treatment withmetals of the class described, namely those having melting points below400 1 completely removes the residual chlorine. As an example of onemethod of treatment by our process the following is given:

500 grams of synthetic oil containing 0.02% chlorine is treated with 1gram of sodium for four hours at 300-350 F. the mixture being stirredvigorously throughout this time with a mechanical stirrer. At the end ofthe four hours the mixture is allowed to cool and methyl alcohol isadded to decompose the excess sodium. When reaction has ceased the oilis diluted with 300 cc.

of gasoline and washed well with hot water. The

gasoline and alcohol are then removed by distillation using externalheating and passing 3 steam through the liquid. No trace of chlorine isfound in the final oil after this treatment. The oil is then suitablefor use as a high quality lubricatingoil, or it may be blended withother oils suitable for lubrication, or it may be added in very smallamounts of 10% to of 1% or less as a solidification inhibitor to oils ofhigh pour point to produce a marked decrease in the pour point of theoil.

While the above example shows the use of sodium for removing chlorinefrom a lubricating oil prepared by condensation of chloro-parafiin witha naphthenic compound in the presence of aluminum chloride it will beunderstood that our process includes the removal of halides from any.

lubricating oil prepared by synthetic means in which either organic ormetallic halides are used. As examples of such oils the following aregiven; oils prepared by condensation of chloro-paraffin through theaction of a high vacuum distillation,.

by the condensation of olefins and similar organic substances withmetallic halides, or by the condensation of organic halides with oleflnsor aromatic compounds. It will also be understood that other reactivemetals having melting points below 400 F. including lithium, potassium,rubidium, caesium and mercury may be used in place of sodium. 7

This invention is not to be limited by any theory of the mechanism ofthe reactions nor to any specific example which may have been given forpurpose of illustration, but only by the following claims in which it iswished to claim all novelty inherent in this invention.

We claim:

1. Process for removing traces of halides from oils produced bycondensation of organic material containing a halide comprising treatingthe liquid oil with a reactive metal in a liquid or molten condition ata temperature below the decomposition temperature of the oil.

2. Process for removing traces of halides from lubricating oils producedby the condensation of organic halides by the action of metallic halideswhich comprises treatment of the condensed liquid oil at temperaturesbelow about 600 F. with a metal which is in a molten condition at thetemperature of treating.

,3. Process for removing traces of halides from lubricating oilsproduced by condensation of organic materials in the presence ofmetallic halides which comprises bringing the condensed liquid oil intocontact at a temperature below 600 F. with the reactive metal in amolten condition.

4. Process according to claim 1 in which a metal from the classcomprising alkali metals and mercury is used.

5. Process according to claim 1, in which sodium is used at atemperature between abou 190 and 450 F.

EDWARD M. JOLLY. CHARLES C. SWOOPE.

